Flash control mechanism for a camera

ABSTRACT

Flash control mechanism automatically switches the connections to elements in an exposure timing circuit in response to the detection of object brightness and an electrically responsive mechanism restrains a release member controlling ignition of the flash unit and rotation of the flash indexing socket into an ignition position.

United States Patent 71191 Imura May 7, 1974 FLASH CONTROL MECHANISM FOR A [56] References Cited CAMERA UNITED STATES PATENTS [75] Inventor: Toshinori Imura, Osaka, Japan 3,535,989 10/1970 Kitai 95/53 EB 3,535,991 10/1970 Kitai 95/53 EB Asslgneel M11101"! Qamera KabushlklKalsha 3,416,421 12/1968 Biedermann etal 95 53 EB sa a-s a aap 3,433,144 3/1969 Ivester Filed p 29 1970 3,537,805 I 11/1970 Michatek 431/93 [21] Appl. No.: 76,392 Primary ExaminerRobert P. Greiner Attorney, Agent, or Firm-Watson, Cole, Grindle & [30] Foreign Application Priority Data Watson Oct. 3, 1969 Japan 44-78610 5 ABSTRACT June 2, 1970 Japan 45-47844 Flash con ro mechanism automatically ch e connections to elements in an exposure timing circuit [52] Cl in response to the detection of object brightness and [51] Int Cl G03) i5/04 6 7/08 an electrically responsive mechanism restrains a re- [58] Fieid 95/11 P R H 5 R lease member controlling ignition of the flash unit and 'E '6'E 53 E rotation of the flash indexing socket into an ignition 431/92, position.

7 Claims, 12 Drawing Figures mmanm H914 (3.810.205

' SHEET a {If 6 5 EFIZ 'EL Y 1 IINVENTOR 11 SHQQNTBQL M CH NISM FOR C AMERA BACKGROUND OF THE INVENTION *The present invention relates to a flash photograph device in a camera provided with anelectric shutter and a detachable multi-lamp photoflash unit, which is automatically controlled by the brightness of an object.

Formerly, in a camera provided with a meter pointer and a detachable multilamp photoflash unit, the brightness of an object was determined by the meter pointer prior to exposure, and when the brightness of an object was higher than a certain brightness EE photography was effected by scanning the position of the meter pointer. When the brightness of an objectwas lower than a certain brightness the camera was changed over to automatic flashphotography, and after exposure the multilamp photoflash unit was turned to make preparations for a subsequent flash photograph.

In such acamera, however, when a multilamp photoflash unit is not attached to the camera it becomes impossible to effect the proper exposure for an object of low brightness, so that in such acase thephotograph is prevented by locking the shutter release.

On the other" hand. an electric shutter may be modified for controlling the exposure of an' object of low brightness as well as an object of high brightness.

SUMMARY OF THE INVENTION The present invention makes use of the special characteristics of an electric shutter, and in accordance with the present invention a flash photograph device includes a photoconductive element in the control circuit for the electric shutter as a detection circuit prior to exposure, to determine the brightness of an object and when the object brightness is higher than a certain value the control circuit effects EE photography regardless of whether or not a multilamp photoflash unit is attached. When the object brightness is low the camera is changed over automatically to effect flash photography and at the same time operate the multilamp photoflash'unit. When a multilamp photoflash unit is not attached to the camera the control circuit controls the exposure of'the electric shutter corresponding to I the brightness of an object of low brightness.

Further, in order to change between EE photography and flash photography the camera is provided with a change over member having a selecting rod engageable with the release operation. The selecting rod is released from engagement with the release operation member by detaching the multilamp photoflash unit from the camera or by thedetection circuit indicating high brightness of an object.

Another feature of the present invention is that the change over member is interlocked with the release operation plate through the-selecting rod whereby the flash bulb ignition device and the multilamp photoflash unit feed lever are operated and also interlocked with the change over member.

A further feature of the present invention is that the flash circuit is closed in connection with the interlocking of the release operation member and the change over member.

And yet another feature of the present invention is that aflash bulb having a mechanical ignition device is put to use and is operated in connection of the interlocking with the release operation member. and the change over member.

The primary object of the present invention is to provide an improved flash control mechanism for indexing a multilamp flash unit in response to detection of object brightness.

A further object of the invention is to provide an improved restraining mechanism for controlling the operation of an index mechanism for a multilamp flash unit.

A still further object of the invention is to provide an improved mechanism for altering the internal connections within an exposure time control circuit in accordance with the object brightness. I

The many other objects and advantages of the present invention will be apparent from the detailed description disclosed hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of the first embodiment in accordance with the present invention.

FIG. 2 is a top view of the operational mechanism of a multilamp photoflash unit of the embodiment shown in FIG. 1.

FIG. 3 is a side view of the embodiment shown in FIG. I, wherein the brightness of an object is high and the flash device is inoperative.

FIG. 4 shows the control circuit for the electric shutter in the embodiment shown in FIG. 1.

FIG. 5 shows the flash circuit in the embodiment shown in FIG. 1.

FIG. 6 is a side view of the second embodiment in accordance with the present invention.

FIG. 7 shows the electric control circuit in the embodiment shown in FIG. 6.

FIG. 8 is a side view of the third embodiment making use of a flash bulb mechanically ignited in accordance with the present invention.

FIG. 9 is a top view of the operational mechanism of the multilamp photoflash unit for the embodiment shown in FIG.'8.

FIG. 10 is a longitudinal side view of the flash bulb forthe embodiment shown in FIG. 8.

FIG. 11 is a bottom view of the multilamp photoflash unit for the embodiment shown in FIG. 8.

FIG. 12 is a perspective view of the ignition device in the embodiment shown in FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to the first embodiment shown in FIGS. 1 to 5 in accordance with the present invention, reference numeral 1 is a sector ring for opening/closing shutter blade 2 and has closing pin 10 mounted thereon, and is biased counter-clockwise by spring 3 as shown by arrow 19 and is checked against movement by a release lever not shown in the drawings, which releases the restraint by pushing down release plate 4.

Release plate 4 is supported on the camera body rotatably by guide slot 4C and pin 5 provided on the camera body and pulled upward by spring 11, and provided with bend-up arm 4a on the side and working protrusion 412 on the tip, and bears contact pieces 7, 9 through insulating member 6, facing respectively contacts 8, 10 on the camera body to form switches S and S 3 "Kassie l st lfiliQQFlYllllflEUlS a.,. .1212.- pivotedon'the camera body by pin 13, and given a counter-clockwise turning tendency by spring 14, and one arm 12a thereof is located in the descending track of working protrusion 4b.

Closing drive lever 15 pivoted on the camera body by pin 16 has a counter-clockwise turning tendency by spring 17 and is provided with pins 15a, 15b respectively on both sides thereof. Restraining edges 15c, 15d composed of two steps are on the circumferential edge of lever 15, and arm 12b of release lever 12 is in contact with pin 15b.

.Closing operation lever 20 pivoted on the camera body by pin 21 is provided with driving arm 20a on one side thereof to engage with closing pin 1a of sector ring 1 and driven arm 20b on the other side faces into the turning track of pin.lb of closing drive lever 15.

Restraininglever 22 pivoted on the camera body by pin 23 has a counter-clockwise turning tendency by spring 24 and is provided on one end thereof with armature 22a cooperating with electromagnet 18 fixed to the camera body. On the other arm neck portion 22b engages with restraining edges c. 15d, and when the electromagnet is excited to attract armature 22a the tip of neck portion 22b engages with restraining edges 15c,

Change over plate 25 is movable up and down and is guided by pin 26 mounted on the camera body and long guide slot 25d is provided on the upper portion thereof with arm 25b projecting to one side to engage with the upper portion of bend-up arm 4a of release plate 4. Working arm 25b projects'to the other side of plate 25, and provided on the lower portion thereof with contact piece 41 for changing over to contacts 42, 43 through an up-and-down motion of insulating member 46 and contact piece 44 for opening/closing contact 45. And, beneath arm 25h there is provided pin 28 on which selecting rod 27 ispivoted to have a counterclockwise turning tendency by spring 29. Selecting rod 27 is ordinarily in contact'with stop pin 256 provided on change over plate 25, and upper end surface 27b thereofois located in the descending track of arm 4a of release plate 4, and on the other side thereof projection 27a on the upper portion and projection 270 on the lower portion are provided.

Intermediate lever 31 is pivoted on the camera body' by pin 32 and has a counter-clockwise turning tendency by spring 33 and is provided on one arm thereof with follow-up arm 310 having a slant for engaging with pin 15b of closing drive lever 15. Bent portion 31b adjoins the slanted surface, and on the other arm thereof working projection edge 31a is formed to be in contact with the outside of projection 270 of selecting -rod 27. v

Flash lever 35 is pivoted on the camera body by pin 36 and has a counter-clockwise turning tendency by spring 37 and is provided on one arm thereof with projection 35a in contact ordinarily with connecting rod 61, and on the other arm thereof working edge 35b for engaging with projection 27a of selecting rod 27 to move it.

'Multilamp photoflash unit feed lever 50 movable horizontally to the right and left relative to the camera body through long slot 50d guided by pin 51 provided on the camera body has a tendency to move to the right through spring 52. The right tip of feed lever 50 forms edge 50a driven by film winding lever 62 described later and step portion b is formed on the side edge on the left thereof. And onto pin 54 mounted on the upper surface thereof there is pivoted feed lever 53 having a clockwise turning tendency through spring 55 in FIG. 2 and on the tip of feed lever 53 feed pawl 53a is formed.

Film winding lever 62 is provided on the camera body by means of a well known mechanism so as to turn together with pin 63, and working pin 62a provided on the upper surface thereof comes into contact with edge 50a of multilamp photoflash unit feed lever 50 located in the right end position in the film winding process, so as to move lever 50 to the left against spring 52.

Restraining portion 38a of one arm of feed check lever 38 is pivoted on the camera body by pin 40 and has a counterclockwise turning tendency by spring 39 in FIG. 1 to engage with step portion 50b of multilamp photoflash unit feed lever 50. Feed lever 50 is checked against movement to the right by spring 52 when portion 38a engages with step portion 50b. And, release arm 38b of feed check lever 38 is located beneath working arm 25a of change over plate 25 to engage with working arm 25a when change over plate 25 descends.

Transmission member is turnable within multilamp photoflash unit holder and is provided with a plurality of projection arms 60a (four in FIG. 2) and mounted on connecting rod 61 supported on the camera body movably up and down and has an ascending tendency. Transmission member 60 is rotatably supported, and has a tendency to hold the position shown in FIG. 2. And, on the top of transmission member 60 there is detachably provided a multilamp photoflash unit having a socket for receiving the same number of flash bulbs (not shown in FIG. 2) as projection arms 60a and when multilamp photoflash unit is attached, connecting rod 61 is pushed down against its ascending tendency and when the multilamp photoflash unit is detached connecting rod 61 ascends to its original posi tion to turn flash lever 35 counter-clockwise.

Next, the formation of a control circuit for the electric shutter in accordance with the present invention will be described hereinafter with reference to FIG. 4, wherein main switch S, connected in series to power source E is opened/closed by contact piece 7 and contact 8. In the power source circuit there are provided photoconductive element C and fixed resistance R in parallel, which are connected to each other through change over switch S composed of contact piece 41 and contacts 42, 43. At node P element C and resistance R trigger switch S for checking time and time constant condenser Q are connected in parallel with each other, and to node 0 switch S and condenser Q switch S composed of contact piece 9 and contact 10 and relative resistance R, are connected in parallel with each other. And, by opening/closing switches S S and S, the brightness detection circuit and the time checking circuit are formed. Node P is connected to the base of first transistor TR, and the collector of first transistor TR, is connected to the base of second transistor TR and in the collector circuit of second transistor TR electromagnetic coil 18 is inserted to form a Schmitt trigger circuit.

In the flash circuit, as shown in FIG. 5, to power source E condenser Q is connected through charging switch S' composed of contact piece 44 and contact 45, and to condenser Q'there isformed a discharge circuit connected to flash'lamp L through synchroswitch S' Where, for example, resistance value R. of the photoconductive element corresponding to the brightness of an object is larger than relative resistance R the brightness ofan object-is low andswitch S is closed'in FIG. 4 and the detectioncircuit formed by open switch S transistor TR, is in a nonconducting state and second transistor TR is in aconducting state,-so that electromagnet l8is excited. However, when the brightness of an object is high andRg R], bothtransistors TR TR are non-conductive and electromagnet ISisdemagnetized.

And, in any case regardless ofthe brightness of an object when both switches S S are closedrelative resistance R, is short cir'cuited; so'thatfirst'transistor TR becomes nonconductive and second transistor TR becomes conductive, andelectromagnet 1 8 is excited.

The following description-assumes that the brightness of an object is low and R 'R and that 'a' multilamp photoflash unit is equippedto the camera.

In the process of the first, stage ofpushing down release plate 4 contact piece 7 comes intocontact with contactS andmain switch'S is closed. Simultaneously therewith from the condition shownin' FlGfl release lever 12 starts to turn clockwise against spring 14 because arm 12a is pushed by working protrusion 45, and releases the restraint of closing drive lever 15. However, as described hereinbefore electromagnet 18 is ex cited, so that restraining lever 22" is attracted to the counter-clockwise turning positionand its neck portion 22b restrains first restraining edge 150 of closing drive lever 15 to check its turning.

F urther. when release plate" 4 is pushd down contact plate 9 comes into contact with contact 10, switch S is closed, and relative resistance R is short-circuited so that electromagnet 18 remains energized andrestraining edge 150 of closing drive lever 15 is still checked by neck portion 22b. At the same time, bend-up arm 4a of release plate 4 pushes down upper end surface 27b of selecting rod 27 to allow change over plate to descend together with: selecting rod 27. And thereby, contact piece 41 movesfrom contact 42 to contact 43 and change over switch is switched, and contact piece 44 comes into contact with contact 45 to close charging switch S for the flash circuit shown in FIG. 5 to charge condenser Q.

Additionally, on account of the switching of switch S resistance R providing a delay suitable for the flash photography is connected" to the time constant circuit instead of photoconductive element C. And at the same time, working arm' 25a of change over plate 25 engages with release arm 38b of feed check lever 38 to turn lever 38 clockwise and rele'asethe engagement of restraining portion 38a of lever 38 and step portion 50b of multilamp photoflash unit feed lever 50. Feed lever 50 is pulled by spring 52 to move to the right end position thereof, and pawl 53 of feed lever 53 moves over projection arm 60a.

' Further, when release plate 4 is pushed down, release plate 4 releases the engagement of the release lever not shown in the drawings and sector ring 1, and sector ring 1 is turned in the direction shown by arrow 19 by spring 3 to release the shutter.

, ln the opening process of the shutter, trigger switch S3 is opened. and condenser 0. starts to be charged by the current running throughfixed resistance R2, and then the shutter closes synchro switch S, and'flash bulb L is ignitedby condenser Q. When condenser-Q is charged to a certain voltage, both transistors TR TR are non-conductive, electromagnet l8 is demagnetized, edge of closing drive lever 15 is released, closing drive lever 15 starts to turn counter-clockwise by spring 17, pin 15b of lever 15 pushes to move driven arm 20b of operation lever 20 to turn it counterclockwise, and driving arm 20a of lever 20 engages with pin la'of' sector ring 1 to turn it clockwise and close shutter sector 2. 1

Next, after release plate 4 completes its descent,

.plate 4 ascends to return to its original position by means of spring 11, release lever 12 is turnedcounterclockwise by spring 14, and arm 12!; of lever 12' engages with pin 15b to move it and turn closing drive lever 15 clockwise to return it to the original position shown in FIG. 1 againstspring l7. Then, upon winding the film by turning film winding lever 62' counterclockwise in FIG. 2, working pin 62a of leverv 62:engages with driven edge 50a on the right end of'multilamp photoflash unit feed lever 50 to move it to the left, and thereby pawl 53a of feed lever 53 engages with projection arm 60a of indexing member 60 to turn it.

counter-clockwise a l/4 turn against the click mechanism. An interchangeable feed to-anew flash bulb is ef fected and in' the terminal process of the pushing step portion 50b engages with restraining portion 38a of feed check lever 38 to be restrained thereby.

In operation, when a multilampphotoflash unit isnot mounted onto the camera flash lever 35 is turned'counterclockwise by spring 37 until connecting rod 61' is held at its ascendingposition, and working edge 35b of lever 35 pushes to move upper projection27a'of selecting rod 27 outward, and turns selecting rod 27 clockwise. Upper end' surface 271) of rod 27 moves to the outside of the descending track of arm 4a of release plate 4 so as not to engage with each other. Thereby, the descending motion of change over plate 25 accompaniedby the descent of release plate 4 is not effected, and accordingly switching of change over switch. S is not effected and in the delay circuit photoconductive element C is .connected. Further, charging switch S for the flash circuit is also not closed. And also, the clockwise turning of feed check lever 38 is not effected, so that restraining portion 38a of lever 38 holds engagement with step portion 50b of multilamp photoflash unit feed lever 50 to check its operation, so that the flash bulb is not ignited. And, because of the pushing down of the release plate 4 the opening of sector ring 1 is started and the opening of the clock trigger causes condenser Q to be charged by the current set by the resistance of photoconductive element C due to low object brightness, and when condenser Q is charged to a certain voltage both transistors TR,, TR are non-conductive and the closing process of the sector is effected in the same way as described hereinbefore, so that a long time exposure suitable for object with low brightness is effected.

Assuming the brightness of an object is high, and R R,, the operation is as follows.

In FIG. I, in the process of the first stage of pushing down release plate 4 main switch S, is closed and arm 12b releases the restraint of closing drive lever 15. At

this juncture, as described 'hereinbefore because of photoconductive element C having a low resistance value and relative resistance R, transistor TR becomes non-conductive, so that electromagnet 18 is demagnetized and neck portion 22b of restraining lever 22 releases the restraint of first restraining edge c of closing drive lever 15. The turning of release lever 12 turns closing drive lever 15 counter-clockwise and consequently intermediate lever 31 turns counter-clockwise to allow pin 15b to contact portion 31b of lever 31 from follow-up arm 31c having a slant surface, and working projection edge 31a oflever 31 pushes lower projection 270 of selecting rod 27 to the left to turn selecting rod 27 clockwise, so that upper-end surface 27b of rod 27 retreats from the descending track of arm 40 to avoid engagement therewith. The follow-up of change over 'second restraining edge 15d of closing drive lever 15, and the subsequent turning of closing drive lever 15 is stopped as shown in FIG. .3.

Further, when release plate 4 is pushed down, as described hereinbefore the shutter release process is started, time checking trigger switch S is opened, condenser Q is charged by the current running through photoconductive element C due to the brightness of an object, and when that condenser is charged to a certain voltage both transistors TR TR are made nonconductive again, electromagnet 18 is demagnetized, the restraint of second restraining edge 15d of closing drive lever 15 effected by neckportion 22b of restraining lever 22 is released. Closing drive lever 15 starts to turn again to operate closing operation lever '20, and thus sector ring 1 is turned in a direction to close sector 2, thereby closing the shutter.

Meanwhile, as described hereinbefore change over plate 25 has been cut off from the follow-up of release plate 4, so thatcharging switch S for the flash circuit is not closed, and eventhougha multilamp photoflash unit is mounted to the camera ignition thereof is not effected. And, change over plate 25 does not release the check of feed check lever 38, so that even though film winding lever 62 is operated after exposure it is possible to prevent an empty feed of the flash bulb which was not ignited.

FIG. 6 and FIG. 7 show a second embodiment in accordance with the present invention, wherein the same parts as those in the first embodiment are denoted by the same symbols.

In the first embodiment, upper end surface 27b of selecting rod 27 on change over plate 25 operated arm 4 of release plate 4 mechanically by turning flash lever and turning intermediate lever 33. However, in the second embodiment, instead electromagnet 30 operates selecting rod 27, that is, spring 29' provides a clockwise turning tendency to selecting rod 27, and two end surfaces 27a, 27b of upper and lower armature are arranged to'face electromagnet 30 fixed to the camera body. Additionally on the arm on the back side of armature 27d slant surface 27e is formed and on the upper end surface 27b of selecting rod 27 notch portion 27'!) is formed. Also, on the release plate 4 push pin 42 for engaging with slant 272 is separately provided and contact piece 64 to be closed at the ascending position of release plate 4 and opened in the descendent process of release plate 4 faces contact 65 on the camera body. Beneath connecting rod 61 there is provided switch 5;, composed of contact pieces 66, 67 to be closed by engagement with a multilamp-photoflash unit and opened by the detachment thereof, and in addition second restraining edge 1511 of closing drive lever 15 is removed.

ln FIG. 7, node P of the detection and delay circuit is connected to the base of third transistor TR in addition to first transistor TR, and the emitter circuit of third transistor TR is connected to the positive pole of the power source and both switches S S and change over electromagnet 30 are inserted in series.

When a multilamp photoflash unit is mounted to the camera and switch S is closed and the brightness of an object is lower than a certain value, as release plate 4 is pushed down, first, main switch S is closed, the detection circuit comprising photoconductive element C and relative resistance R, is formed, and electromagnet 18 is demagnetized. However, switch S has been closed so that change over electromagnet 30 is excited, selecting rod 27 is attracted thereby, and upper end surface 27b of rod 27 remains in the descending track of arm 4a of release plate 4 to come into contact with each other. Arm 4a engages notch step 271) to descend as a body with change over plate 25. In this case, electromagnet 18 is demagnetized so that restraining lever 22 is deprived of its restraining function; however, closing drive lever 15 is pushed by release lever 12 and checked thereby.

Then, switch S is opened and change over electromagnet 30 is demagnetized, however, arm 4a and notch step 27b hold their engaged relationship. Next, switch S is closed, relative resistance R is short-circuited, electromagnet 18 is excited, and restraining lever 22 checks closing drive lever 15 along with release lever 12. Then, release plate 4 starts to turn release lever 12,

' however, closing drive lever 15 is still restrained by rechange over plate 25 change over switch 5, moves from contact 42 to contact 43, and resistance R is connected to the delay circuit and at the same time the charging of condenser Q in the flash circuit is started by the closing of switch S Release plate 4 releases set ring 1, sector 2 starts to open and at the same time trigger switch S is opened, condenser 0 starts to be charged, synchro switch S is closed in synchronization with the opening of sector 2, and a flash bulb is ignited. Meantime, change over plate 25 turns feed check lever 38 to release the engagement of restraining portion 38a thereof and multilamp photoflash unit feed lever 50, and the multilamp photoflash unit is pulled by spring-52 to move to the right end position.

When condenser Q is charged to a certain voltage transistors TR TR are made non-conductive, electromagnet 18 is demagnetized, closing drive lever 15 is turned to operate lever 20, and sector ring 1 is turned clockwise to close the sector 2.

Because of the operation of film winding lever 62 multilamp photoflash unit feed lever 50 returns to its original position, and meantime indexing member 60 is turned and a new flash bulb is fed to the socket position.

. face 27b of said rod 27 retreats from the descending track of arm 4a so as not to engage'with each other. And change over plate 25 does not-descend, so that change over switch s alsodoes not operate and accordingly the long time exposure due to the resistance value of photoconductive element-C corresponding'to the brightness of an object is effected.

Next, when the'brightness of an object-is high, even though a multilampphotoflashunit is mounted and switch S is closed third transistor TR- is in the nonconductive state when the detection'circuit is formed by the closing of main switch 8,, so thatchange over electrom agnet 30 is not excited, therefore, in the same way as described hereinbefore, asreleaseplate 4 descends selecting rod 27 is turned-clockwise by spring 29' while slant surface 27e is in contact with pin 4e, and upper end surface 27b retracts from the descending track of arm 4a.

Then, switch S is opened, so that even though switch S is closed and relative resistance'R',;isshort-circuited change over electromagnet 30'remains demagnetized, change over plate 25 remains in an immovable position, change over switch S, isnotchanged over, charging switch S is not closed; and feedcheck lever 38 restrains multilamp photoflash unit feed lever 50, so that the flash bulb is not ignited. The exposure corresponding to the brightness of an object is effected, and the feed turning of the multilamp photoflash unit is not carried out.

Next, in the third embodiment shown in FIG. 8 and FIG. 9 in accordance with the present invention, instead of a flash bulb electrically ignited a flash bulb ignited by a mechanical impact to the impact area thereof is put to use.

The formation of such a flash bulb and an ignition device thereof will be described hereinafter in connection with FIGS. 10 to 12. The base of globe 81 of flash bulb 80 is fixed to 4 alloy tube 82 in a blind tube shape. The side of tube 82 forms impactarea 83 and near the tip thereof crimp 84 is formed. In alloy tube 82 anvil 85 composed ofa chemical compound projects into globe 81 and the anvil head thereof is restrained by crimp 84, and between impact area 83 and crimp 84 double primer coat 87 is arranged. On the base in globe 81 is alloy anvil 89 through glass bead 88 and from the base of alloy tube 82 fired primer detection spot 90 and blue dot 91 are supported by a wire. In globe 81 zirconium foil 92 and oxygen atmosphere 93 are enclosed.

Flash bulb 80 is ignited by tapping mechanically impact area 83 by means ofa torsion spring 94 or the like. On the bottom of multilamp photoflash unit 77 there are formed holes 78 in which the tip of alloy tube 82 of blash bulb 80 is fitted and arcuated holes 79 described later in which slide rod 73 is fitted as shown in FIG. 11, and as shown in FIG. 12 in the inside of unit 77 torsion spring 94 is arranged. That torsion spring is in the form ofa piano wire bent into a numeral 8 shape and composed of short restraining portion 96 bent at right angles from fitting portion 95. U-Ietter shaped energizing portion 97 is bent from fitting portion 95, and tapping portion 98 is formed on the end thereof. Tapping portion 98-is restrained by.restraining portion-.96, however, when this engagement is-broken by sliderod 73 which dashes through arcuated hole tapping portion v 98 taps impact area 83 of flash bulb 8 0through; the

elastic energy accumulated therein to ignite the flash bulb.

The third embodiment shown inFIG. 8 and FIG. 9

makes use of the flash bulb ignited mechanically as described above and is not provided with switch S composed of contact piece 44and contact45"as in the, first embodiment shown in FIG. 1. However, the other formation of change over. plate-25 is the same as that in the first embodiment, and release plate 4, selecting rod 27, intermediate lever 31,.release lever 12, closingdrive lever 15 providedwith two restraining edges 15c and 15d, the relativeformation of electromagnet 1.8 operated by the electric control circuit and restraining lever 22, feed check lever 38, connecting rod 61 for the multilamp photoflash unit, and transmission member 60 are also the sameas those in the first embodiment.

The different structure than the first embodiment, is as follows.

In multilamp photoflash unit feed lever 50 there is formed. on the side edge thereof projecting step 5 0e with which one arm. a of tapping lever 70 engages. Tapping lever 70 is connected to the camera body by pin 71 and arm 70a is provided with spring 72 to provide a clockwise turning tendency to tapping lever 70. On the other arm of tapping lever 70there are provided end piece 70c on the tip thereof; and working piece 70b. Facing working piece 70b there is provided slide rod 73 for operating the ignition rod for the flash bulb.

Synchro lever 74 is connected to the camera body by pin 75 and has a clockwise turning tendency by spring 76 and has tip 74h ofone arm facing the exterior of sector ring 1. On the other arm thereof restraining projection 74a is formed, which engages end piece 700 of tapping lever 70. On sector ring I there is provided riser lb for engaging with tip 74b to turn synchro lever 74 counter-clockwise against spring 76 when the sector ring turns in the direction shown by arrow 19.

Since the structure is as described'above whenever the operation the shutter is effected riser lb-turns synchro lever 74 to disengage it from tapping lever 70. However, when EE photography is carried out change over plate 25 does not descend, so that projecting step 50e of multilamp photoflash unit feed lever 50, the movement to the right of which by spring 52 is checked by feed check lever 38, restrains the clockwise turning provided by spring 72 of tapping lever 70, so that the flash bulb is not ignited. However, when flash photography is carried out, as release plate 4 descends change over plate 25 turns feed check lever 38 clockwise and releases the restraint of multilamp photoflash unit feed lever 50 from moving to the right, and lever 50 moves to the right by means of spring 52. When lever 50 disengages from tapping lever 70 because of the turning V of synchro lever 74 tapping lever 70 is suddenly turned clockwise by spring 72 and working piece 70b of said lever 70 taps slide rod 73 to operate the ignition rod (not shown in the drawings) of the flash bulb so as to ignite the flash bulb.

And, as a result of the turning of film winding lever 62 when multilamp photoflash unit feed lever 50 returns to the left feed lever 53 turns indexing member 60 and turns themultilamp photoflash unit to allow the subsequent flash bulb to be located on slide rod 73.

I claim:

1. In a photographic camera having an indexing socket for receiving a multilamp flash unit, a flash control mechanism comprising:

a shutter release member;

an electric delay circuit including a photoelectric element and a condenser;

an exposuretime controlling circuit including a switching circuit and an electromagnet;

a fixed resistance connected parallel to said photoelectric element and forming a flash delay circuit with said condenser;

a change-over switch for selectively connecting said photoelectric element and said resistance to said condenser;

an electric controlling member operated selectively by said electric delay circuit;

a change-over member including said socket interlocking with said shutter release member by said controlling member when the brightness of an object is lower than a predetermined value and operating said change-over switch to connect said resistance to said condenser in said electric delay circuit;

check means interlocked with the operation of said controlling member for preventing the ignition of said flash unit when the brightness of an object is higher than said predetermined value;

an indexing member operative from a first position to a second position to index said socket in an ignition position; and

a restraining member which restrains said indexing member dislaced from said second position to said first position, said restraining member is interlocked with the operation of said change-over member to release the restraint of said indexing member.

2. A flash control mechanism as set forth in claim 1, wherein said change over member connects said photoconductive element to said delay circuit through said change over switch and said exposure time controlling circuit controls exposure of the shutter in accordance with the brightness of an object with a multilamp photoflash unit inserted in said indexing socket.

3. A flash control mechanism as set forth in claim 1, wherein said change over switch includes a normally open contact and said contact is closed with said change over member interlocked with said shutter release member.

4. A flash control mechanism as set forth in claim 1,

further comprising a multilamp flash unit sensing switch serially connected to said change over switch and said electric controlling member whereby both said switches are closed with said multilamp flash unit attached to said camera and said electric controlling member is actuated by operation of said electromagnet.

5. In a camera having an indexing socket for receiving a multilamp photoflash unit, a flash control mechanism comprising:

' a release operation member;

a sector ring having a projection for engaging said release operation member;

an electric control circuit including a photoconductive element, a fixed resistance. a capacitance and an electromagnet;

a switch mounted to said release operation member for connecting said photoconductive element to said capacitance for the detection of the brightness of an object;

a change over member having a change over switch;

a selecting rod connected to said change over member and engageable with said release operation member;

a member for engaging with said selecting rod to interlock therewith with said multilamp photoflash unit attached to said camera;

a check member for interlocking with said change over member and including a tapping lever and a synchro lever for restraining said tapping lever and engaging with said sector ring projection to release restraint by said synchro lever;

a multilamp photoflash unit feed member restrained I by said check member, a tapping lever for engaging with said multilamp photoflash unit feed member and having a hammer, and a synchro lever for restraining said tapping lever and engaging with the synchro projection of said sector ring to release said restraint;

a flash ignition device;

whereby with the brightness of an object lower than a certain value said selecting rod is engaged with said release operation member to displace said change over member, and said change over switch connects said photoconductive element to said fixed resistance and simultaneously releases the restraint of the multilamp photoflash unit feed member and with said multilamp photoflash unit feed member disengaged from said tapping lever and said sector ring projection disengages'said synchro lever from said tapping lever, said tapping lever ignites the flash bulb in said multilamp flash unit;

6. ln a camera having an indexing socket for receiving a multilamp photoflash unit, a flash control mechanism comprising:

a release operation member;

an electric control circuit including an electric delay circuit comprising a photoconductive element and a condenser, a switching circuit and an electromagnet;

a switch provided on said release operation member for connecting said photoconductive element to said condenser to form the detection circuit for the brightness of an object;

a change over member provided with a change over switch;

a fixed resistance connected to said electric control circuit by said change over switch;

a selecting rod connected to said change over member and engageable with said release operation member;

a member for engaging with said selecting rod to interlock therewith with said multilamp photoflash unit mounted in said indexing socket;

a restraining lever having an armature operated by said electromagnet;

a driving lever provided with first and second pawls engageable with said restraining lever;

a check member for engaging with said change over member to restrain indexing of said indexing socket; and a flash ignition device; whereby with the brightness of an object higher than a certain value, said restraining lever operated by said electromagnet disengages from said first pawl to turn said driving lever, and said driving lever disconnects the engagement of said selecting rod and said release operation lever, and said electric control circuit controls the shutter in accordance with the brightness of an object and simultaneously said change over member restrains the indexing of said indexing socket and the flash ignition device; and with the brightness of an object lower than a certain value, said electromagnet holds the engagement of the restraining member and said first pawl.

7. A flash control mechanism as set forth in claim 6,

wherein said multilamp photoflash unit includes a feed lever, a transmission member having a projecting arm engageable with said feed lever and connecting rod;

said multilamp photoflash unit includes a plurality of fitting holes for a flash bulb which contains a chemical compound having a double primer coat. a zirconium foil, and oxygen atmosphere and has an impact area on its'side, and further includes arcuate-shaped slots of the same number as said fitting holes and a torsion spring restrained in said arcuate-shaped slots by the restraining portion thereof and facing said arcuate-shaped slots; and with said multilamp photoflash unit mounted in said socket said arcuate-shaped slots are located on the slide rod of the camera, said slide rod passes through said arcuate-shaped slot to disconnect the engagement of the restraining portion and the torsion spring and said torsion spring taps said impact area to ignite the flash bulb. 

1. In a photographic camera having an indexing socket for receiving a multilamp flash unit, a flash control mechanism comprising: a shutter release member; an electric delay circuit including a photoelectric element and a condenser; an exposure-time controlling circuit including a switching circuit and an electromagnet; a fixed resistance connected parallel to said photoelectric element and forming a flash delay circuit with said condenser; a change-over switch for selectively connecting said photoelectric element and said resistance to said condenser; an electric controlling member operated selectively by said electric delay circuit; a change-over member including said socket interlocking with said shutter release member by said controlling member when the brightness of an object is lower than a predetermined value and operating said change-over switch to connect said resistance to said condenser in said electric delay circuit; check means interlocked with the operation of said controlling member for preventing the ignition of said flash unit when the brightness of an object is higher than said predetermined value; an indexing member operative from a first position to a second position to index said socket in an ignition position; and a restraining member which restrains said indexing member dislaced from said second position to said first position, said restraining member is interlocked with the operation of said change-over member to release the restraint of said indexing member.
 2. A flash control mechanism as set forth in claim 1, wherein said change over member connects said photoconductive element to said delay circuit through said change over switch and said exposure time controlling circuit controls exposure of the shutter in accordance with the brightness of an object with a multilamp photoflash unit inserted in said indexing socket.
 3. A flash control mechanism as set forth in claim 1, wherein said change over switch includes a normally open contact and said contact is closed with said change over member interlocked with said shutter release member.
 4. A flash control mechanism as set forth in claim 1, further comprising a multilamp flash unit sensing switch serially connected to said change over switch and said electric controlling member whereby both said switches are closed with said multilamp flash unit attached to said camera and said electric controlling member is actuated by operation of said electromagnet.
 5. In a camera having an indexing socket for receiving a multilamp photoflash unit, a flash control mechanism comprising: a release operation member; a sector ring having a projection for engaging said release operation member; an electric control circuit including a photoconductive element, a fixed resistance, a capacitance and an electromagnet; a switch mounted to said release operation member for connecting said photoconductive element to said capacitance for the detection of the brightness of an object; a change over member having a change over switch; a selecting rod connected to said change over member and engageable with said release operation member; a member for engaging with said selecting rod to interlock therewith with said multilamp photoflash unit attached to said camera; a check member for interlocking with said change over member and including a tapping lever and a synchro lever for restraining said tapping lever and engaging with said sector ring projection to release restraint bY said synchro lever; a multilamp photoflash unit feed member restrained by said check member, a tapping lever for engaging with said multilamp photoflash unit feed member and having a hammer, and a synchro lever for restraining said tapping lever and engaging with the synchro projection of said sector ring to release said restraint; a flash ignition device; whereby with the brightness of an object lower than a certain value said selecting rod is engaged with said release operation member to displace said change over member, and said change over switch connects said photoconductive element to said fixed resistance and simultaneously releases the restraint of the multilamp photoflash unit feed member and with said multilamp photoflash unit feed member disengaged from said tapping lever and said sector ring projection disengages said synchro lever from said tapping lever, said tapping lever ignites the flash bulb in said multilamp flash unit.
 6. In a camera having an indexing socket for receiving a multilamp photoflash unit, a flash control mechanism comprising: a release operation member; an electric control circuit including an electric delay circuit comprising a photoconductive element and a condenser, a switching circuit, and an electromagnet; a switch provided on said release operation member for connecting said photoconductive element to said condenser to form the detection circuit for the brightness of an object; a change over member provided with a change over switch; a fixed resistance connected to said electric control circuit by said change over switch; a selecting rod connected to said change over member and engageable with said release operation member; a member for engaging with said selecting rod to interlock therewith with said multilamp photoflash unit mounted in said indexing socket; a restraining lever having an armature operated by said electromagnet; a driving lever provided with first and second pawls engageable with said restraining lever; a check member for engaging with said change over member to restrain indexing of said indexing socket; and a flash ignition device; whereby with the brightness of an object higher than a certain value, said restraining lever operated by said electromagnet disengages from said first pawl to turn said driving lever, and said driving lever disconnects the engagement of said selecting rod and said release operation lever, and said electric control circuit controls the shutter in accordance with the brightness of an object and simultaneously said change over member restrains the indexing of said indexing socket and the flash ignition device; and with the brightness of an object lower than a certain value, said electromagnet holds the engagement of the restraining member and said first pawl.
 7. A flash control mechanism as set forth in claim 6, wherein said multilamp photoflash unit includes a feed lever, a transmission member having a projecting arm engageable with said feed lever and connecting rod; said multilamp photoflash unit includes a plurality of fitting holes for a flash bulb which contains a chemical compound having a double primer coat, a zirconium foil, and oxygen atmosphere and has an impact area on its side, and further includes arcuate-shaped slots of the same number as said fitting holes and a torsion spring restrained in said arcuate-shaped slots by the restraining portion thereof and facing said arcuate-shaped slots; and with said multilamp photoflash unit mounted in said socket said arcuate-shaped slots are located on the slide rod of the camera, said slide rod passes through said arcuate-shaped slot to disconnect the engagement of the restraining portion and the torsion spring and said torsion spring taps said impact area to ignite the flash bulb. 